柚皮苷二氢查尔酮抗氧化活性的构效关系研究

采用DPPH自由基清除实验和Materials Studio 软件中的DmoL3程序对柚皮苷二氢查尔酮的DPPH自由基清除率、几何结构和性质（振动频率、反应活性及热力学性质）进行了理论研究,得到了分子的抗氧化活性数据、稳定几何构型、各原子上的电荷分布、热力学性质、Fukui指数和前线分子轨道参数,计算结果表明柚皮苷二氢查尔酮具有较高的反应活性,分子中酚羟基上的氧原子是影响其反应活性的主要部位,也是发生亲电反应的活性位点,表现出较强的抗氧化性,当柚皮苷二氢查尔酮浓度为0.3mg•mL-1时,DPPH自由基清除率达到86.49%。     

柚皮苷二氢查尔酮抗氧化活性的构效关系研究

采用DPPH自由基清除实验和Materials Studio软件中的DmoL~3程序对柚皮苷二氢查尔酮的DPPH自由基清除率、几何结构和性质(振动频率、反应活性及热力学性质)进行了理论研究,得到了分子的抗氧化活性数据、稳定几何构型、各原子上的电荷分布、热力学性质、Fukui指数和前线分子轨道参数,计算结果表明柚皮苷二氢查尔酮具有较高的反应活性,分子中酚羟基上的氧原子是影响其反应活性的主要部位,也是发生亲电反应的活性位点,表现出较强的抗氧化性,当柚皮苷二氢查尔酮浓度为0.3mg·mL~(-1)时,DPPH自由基清除率达到86.49%.     

小麦超弱延迟发光测试系统

应用一种新型高灵敏度光电倍增管作为传感器,设计一套用于检测小麦超弱发光的光子计数测量系统,实现对储藏小麦超弱发光的定量测量.适当安排LED阵列分布,设计适合延迟发光需要的照明系统,通过对白光LED光源辐射等效单光子能量和流明效率的计算,建立起光照度与光子数强度之间的联系,实现了光源照射强度与样品延迟发光强度之间的定量比较.对不同光照强度下小麦样品延迟发光的测试和双曲函数拟合,探讨了小麦超弱延迟发光双曲函数拟合参量的变化规律;发现不同照射强度下存在不同的饱和照射时间;小麦超弱延迟发光强度曲线符合双曲衰减规律,超弱延迟发光持续时间达数小时.通过对光照时间和数据采集时间的精确控制,以及在拟合函数中设置延迟时间参量因子,实现了延迟发光测试数据对应时间点的精确标定.     

Modeling of a millimeter wave planar Schottky diode using both improved equivalent circuit model and 3D-EM model

In this paper, a planar Schottky varistor diode is studied and modeled by equivalent circuit method and three dimensional full wave electromagnetic (3D-EM) method, respectively. The diode's equivalent circuit is extracted from millimeter-wave small-signal S-parameter measurements. Since the package of the diode influences the electromagnetic field distribution at millimeter and sub-millimeter wavelengths, a 3D-EM model and an improved equivalent circuit model is applied to describe the field precisely. The simulated results of equivalent circuit, improved equivalent circuit and 3D-EM model are compared with the measured results. In addition, the effects caused by silver paste conductive adhesive are considered in 3D-EM model and improved equivalent circuit model. The results show that both the 3D-EM model and improved equivalent circuit model have good S-parameter consistency with measured results.     

Equivalent cross-relaxation rate imaging positively correlates with pathological grade and cell density of adipocytic tumors

Objective

Equivalent cross-relaxation rate imaging (ECRI) is an MRI technique used to evaluate qualitative changes in protein-water interactions. We aimed to prospectively evaluate the utility of ECRI for classification of adipocytic tumors.

Materials and Methods

Institutional Review Board approval was obtained and all patients provided informed consent. Study participants included 40 patients with adipocytic tumors who were diagnosed with lipomas (n = 22), atypical lipomatous tissue/well-differentiated liposarcoma (ALT/WDL; n = 9), myxoid/round cell liposarcoma (MyL; n = 6), and dedifferentiated liposarcoma (DDL; n = 3), and 20 control patients for whom subcutaneous fat in the buttock or thigh was analyzed.

Results

Mean ECR values of lipomas, ALT/WDL, and subcutaneous fat were low, and those of MyL and DDL were high. Mean ECR values of MyL and DDL were significantly higher than those of ALT/WDL. The cut-off value was 5.1%. There was a positive correlation between ECR value, pathological grade, and cell density in adipocytic tumors.

Conclusion

The ECR value positively correlates with pathological grade and cell density of adipocytic tumors. Our findings suggest that ECRI is a useful method for preoperative evaluation of adipocytic tumors.     

基于等效节点的子孔径拼接系统公差分析

在子孔径拼接系统中,各子孔径之间的倾斜与位移对整个系统的成像质量有直接影响.本文应用动态光学理论中等效节点概念,根据各个子孔径倾斜及轴向与垂轴位移位移时等效节点也将发生相应移动的原理,利用拼接元件形成像点的位移引起的各个子镜形成像点叠加误差形成的弥散圆尺寸变化之间的关系,简化了子孔径倾斜与位移对拼接系统像质影响的分析与计算.通过在子孔径拼接原理样机结构设计与公差分析中的应用,得出原理样机的倾斜公差为4 μrad,位移公差为6 μm,使原理样机的子孔径装配调整得到了有效控制.     

Direct evaluation of the equivalent linear damping for TLCD systems in random vibration for pre-design purposes

Passive control of structural vibrations has received in recent years a great attention from researchers concerned with vibration control. Several types of devices have been proposed in order to reduce the dynamic responses of different kinds of structural systems. Among them, the Tuned Liquid Column Damper (TLCD) proved to be very effective in reducing vibration of structures. Since the increasing use of TLCDs in practical realizations, this paper aims at developing an approximate formulation, by means of a statistical linearization technique, able to estimate the parameters of a structure equipped with a TLCD subjected to random loads for pre-design purposes. Moreover, it is shown that results obtained via Monte Carlo approach on the non-linear system are in good agreement with those obtained by means of the proposed formulation.     

等效电子耦合原子态的二维关系表格计算

用专门处理二维关系的FoxPro编程给出计算等效电子LS耦合原子态的计算方法并作出简化,具体计算了f7电于组态的LS耦合原子态。     

在满足广义指数型二分性条件下的线性化

本文将Ｈａｒｔｍａｎ线性化定理和Ｐａｌｍｅｒ线性化定理推广到具有广义指数型二分性的系统,证明了等价函数的强一致连续性;作为应用,在例子中给出了一类系 统的稳定性的判别方法．     

球型胶体颗粒的表面电位和表面电荷密度的关系

胶体颗粒的表面电荷密度和表面电位之间的关系是颗粒表面的基本性质之一．要确定这个关系,需要解Poisson-Boltzmann(PB)方程,求出颗粒外的电位分布．然而对于球形颗粒,PB方程却没有解析解．Loeb等,求出了数值解,近似解析表达式虽然很多,也比较复杂,